Fishing tool for wells



Oct. 17, 1950 sc u 2,525,954

FISHING TOOL FOR WELLS Filed Sept. 19, 1947 BRUNO R. SGHABARUM IN VEN TOR.

ATTORNEY Patented Oct. 17, 1950 UNITED STATES PATENT OFFICE FISHING TOOL FOR WELLS Bruno R. Schabarum, Midland, Tex., assignor to Carl B. King Drilling Company, Midland, Tex., a corporation of Delaware Application September 19, 1947, Serial No. 774,909

2 Claims. 1

This invention relates to a fishing tool for use in connection with rotary drilling, and particularly to a type of tool commonly termed in oil field parlance a junk basket. The purpose of such a tool is to effect removal of metallic or other foreign objects, such as bit cones and other parts of the drilling tools, which have been broken in the course of drilling and collect in the bottom of the well where they will interfere with eiiicient drilling unless removed. Removal of such foreign objects by means of a tool in accordance with this invention is' accomplished by flowing the circulatingdrilling mud stream in a direction to wash the objects into the interior of the tool where they are trapped and collected for removal upon withdrawal of the tool from the well.

It is a primary object of this invention to provide an improved form of fishing tool or junk basket which is relatively simple in construction and efficient in operation, and which may be withdrawn from the well without substantially reducing the fluid column in the well. v

ther and more specific objects and advantages of this invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings which illustrate one useful embodiment in accordance with this invention.

In the drawings:

Fig. l is a longitudinal sectional view of a tool in accordance with this invention;

Fig. 2 is a generally diagrammatic view showing the tool in a position in a well; and

Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. 1.

Referring to the drawings, the tool comprises a generally tubular body member is having a hollow bore ii communicating at its upper end with the usual internally threaded box l2 for threaded attachment to a conventional string of drilling pipe i3 (Fig. 1), or other suitable pipe string. The lower end of bore II is provided with an internal shoulder M adapted to form an annular seat it on its upper face for the reception of a ball check valve 16. With this valve arrangement, fluid is permitted to flow in the upward direction only through bore ii. A passageway ii extends through the wall of body ii] intermediate ball check valve IE5 and box I2 to.

provide communication between the exterior of the tool and bore ii. A rupturable disk it, constructed of any suitable metal or other material adapted to rupture at a pre-determined pressure,

is seated across passageway ii, to form a closure therefor and is held in place by means of a hollow threaded bushing is inserted into the outer end of passageway ll.

The lower end of body it below check valve I6 is enlarged somewhat in external diameter and substantially in internal diameter, and threaded externally at its lower end. A plurality of axially aligned, collar members 20-20, internally threaded at their upper ends and all but the lowermost one externally threaded at their lower ends, are screwed together and the group screwed on the lower end of body Hi to form an extension thereof. The lowermost one of the collar mem bers 20 is providedwith serrated lower edgeto form a shoe 2i for the lower end of the tool. Each of the collar members 2! is provided at about its mid-point with an inwardly extending annular shoulder 22 which faces the adjacent end of the collar member next above it, forming with the latter a pair of relatively movable cooperating abutments.

Mounted transversely of each of the collar members inside the tool is a disk-shaped catcher element, each designated generally by the numeral 23, constructed of rubber or other rubberlike resilient material. The diameter of the catcher elements is slightly greater than that of the bore of the collars so that their peripheries will extend between the abutments formed by the shoulders 22 and the lower ends of the adjacent collar members, whereby when the collar members are screwed together, the edges of catcher elements 23 will be tightly gripped between these abutments and form fluid-tight seals therebetween. The peripheries of catcher elements 23 are preferably provided with annular beads 24 which are adapted to be seated in complementary recesses formed in the abutments to firmly lock the elements into the collar members. Each of the catcher elements 23 is axially apertured, the apertures being in the form of hollow. upwardly; converging conical nozzles 25 which are molded or formed integrallywith the disk-shaped bodies of the catcher elements A plurality of angularly spaced reinforcing webs 26 extend from the upper ends of each of the nozzles to the upper surface of the disk-shaped body of the catcher element.

The device is employed in the following manner, reference being had to Fig. 2 in this connection: The tool is connected to the lower end of the string of pipe it which is inserted in a well bore 2? through the usual surface casing 28, which is provided with a, side connection 39. The upper end of the drill pipe is provided with a pipe connection 30 in which is interposed a valve 35.,

To operate the tool reverse circulation of the drilling fluid ,is employed, that is, the drilling fluid is introduced into the well bore through connection 29 and flows down into the well through bore and the exterior of the drilling pipe and tool and then flows into the lower end of the tool through shoe 2| and thence upwardly through the interior of the drill pipe to the surface where it is discharged through pipe connection 36 and valve 3|. As the fluid, under pressure of the usual mud pumps (not shown), flows over the bottom of the well and into the interior of the tool, it will wash the undesirable pieces of foreign matter into the interior of the tool where, under the pressure and velocity of the circulating fluid, the solid particles of the foreign matter are forced upwardly into the nozzles 25. Being constructed of resilient material, the outlets of the nozzles will expand sufficiently beyond their nominal diameters to permit the passage therethrough of foreign objects up to sizes somewhat larger than the nozzle diameters. The objects after passing through the nozzles will enter an area of relatively reduced velocity of the fluid and will settle about the exterior of the nozzles and become trapped inside the body of the tool between the catcher elements. The diameter of the nozzle mouths may be the same in all cases or may be, as illustrated, reduced in one or more of the upper ones of the catcher elements so that the latter will catch particles of smaller diameter than are caught by the lower catcher elements. The drilling fluid after passin the several catcher elements will flow upwardly into bore ll, ball check valve l6 lifting to permit this movement, and will travel to the surface through the interior of the drill pipe and out through pipe connection 36. Ball check valve i6 will prevent the fluid from flowing back through the tool and will thereby prevent the foreign matter from being washed or forced back through the catcher elements by the fluid in the interior of the drill pipe string.

When it is desired to remove the tool and the trapped articles from the well, circulation will be reversed at the top of the well to pump the fluid into the interior of the drill pipe. Check valve 16 will close, of course, and pressure will be built up in the drill pipe to exceed the bursting pressure of disk l8 rupturing the latter and opening passageway I1. Thereafter, as the string is withdrawn from the well, the column of fluid in the string above ball check valve 16 will flow out of the drill pipe into the well bore through passageway ll so that none of the drilling fluid will be withdrawn from the well with the removal of the drill pipe and the tool. This has several advantages, in that it is desirable to retain the full pressure of the column of fluid in the well when the drill pipe and tool are withdrawn in order to obviate the danger of blowouts. Also, in the absence of a means such as rupturable disk 23, fluid would be carried out of the well inside the drill pipe and if then, as in normal operation, the sections of drill pipe ar unscrewed in removing the string from the well, large quantities of the fluid would spill out on the derrick floor and on the operators, obviously, very objectionable condition, in addition to resulting in a loss of substantial quantities of drilling fluid. It will be evident that various other forms of pressure actuated valve mechanisms well known to those skilled in the art, may be employed in place of rupturable disk E8 to release the fluid inside the drill pipe before the latter is removed from the well.

It will be understood that the tool in accordance with this invention may include any desired number of catcher elements and that the nozzle apertures may all be of the same or different diameters arranged as noted above.

Moreover, while it is preferable to construct the catcher elements, including nozzles 25, as integral units from suitable resilient material because of the greater ease of manufacture and assembly, if desired, the disk portions may be made of metal and only the nozzle members of resilient material and attached to the disk portions in any conventional manner. Also it will be understood that the diameter of the tool may be varied depending upon the diameter of the well bore in which it is to be run and upon the relative size of the foreign objects which it is designed to catch.

The reverse circulation employed for the operation of the tool may be efiected by the reversing the conventional circulation at the top of the well in the manner above described, or reverse circulation may be effected by the use of a circulation reversing tool, such as thatdisclosed in my co-pending application Serial No. 774,910, filed September 19, 1947.

It will also be understood that various other alterations and changes may be made in the details of this invention without departing from the scope of the appended claims but within the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A fishing tool, comprising, a tubular body adapted for connection to a pipe string to be run in a well bore, check valve means in the bore of said body intermediate the ends thereof arranged to permit only upward flow of fluid through said body, and a plurality of vertically spaced catcher elements comprising hollow upwardly converging nozzle members constructed of flexible resilient material mounted transversely of the bore of said body below said valve means, the discharge openings of said nozzle members being of decreasing diameter in ascending order in said body.

2. A fishing tool, comprising, a tubular body adapted for connection to a pipe string to be run in a well bore, check valve means in the bore of said body intermediate the ends thereof arranged to permit only upward flow of fluid through said body, a plurality of vertically spaced catcher elements comprising hollow upwardl converging nozzle members constructed of flexible resilient material mounted transversely of the bore of said body below said valve means, the discharge openings of said nozzle members being of decreasing diameter in ascending order in said body, a fluid discharge passageway extending through the wall of said body above said valve means, and a closure for said passageway adapted to be opened in response to predetermined fluid pressure exerted thereon.

BRUNO R. SCI-LABARUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 582,828 McGregor May 18, 1897 2,090,616 Erwin Aug. 24, 1.937 2,216,268 Fritsche Oct. 1, 1940 P 2,220,989 Brauer Nov. 12, 1940 2,307,658 Appleby Jan. 5, 1943 2,416,613 Costin Feb. 25, 1947 

